Atmosphere (대기)

Korean Meteorological Society (한국기상학회)
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A Study on Sensitivity of Pollutant Dispersion to Inflow Wind Speed and Turbulent Schmidt Number in a Street Canyon

도시 협곡에서 유입류 풍속과 난류 슈미트수에 대한 대기오염물질 확산의 민감도 연구

  • Wang, Jang-Woon (Department of Environmental Atmospheric Sciences, Pukyong National University) ;
  • Kim, Jae-Jin (Department of Environmental Atmospheric Sciences, Pukyong National University)
  • 왕장운 (부경대학교 환경대기과학과) ;
  • 김재진 (부경대학교 환경대기과학과)
  • Received : 2015.08.17
  • Accepted : 2015.11.30
  • Published : 2015.12.31
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Abstract

In this study, sensitivity of inflow wind speed and turbulent Schmidt number to pollutant dispersion in an urban street canyon is investigated, by comparing CFD-simulated results to wind-tunnel results. For this, we changed systematically inflow wind speed at the street-canyon height ($1.5{\sim}10.0m\;s^{-1}$ with the increment of $0.5m\;s^{-1}$) and turbulent Schmidt number (0.2~1.3 with interval of 0.1). Also, we performed numerical experiments under the conditions that turbulent Schmidt numbers selected with the magnitude of mean kinetic energy at each grid point were assigned in the street canyon. With the increase of the inflow wind speed, the model underestimated (overestimated) pollutant concentration in the upwind (downwind) side of the street canyon because of the increase of pollutant advection. This implies that, for more realistic reproduction of pollutant dispersion in urban street canyons, large (small) turbulent Schmidt number should be assigned for week (strong) inflow condition. In the cases of selectively assigned turbulent Schmidt number, mean bias remarkably decreased (maximum 60%) compared to the cases of constant turbulent Schmidt number assigned. At week (strong) inflow wind speed, root mean square error decreases as the area where turbulent Schmidt number is selectively assigned becomes large (small).

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References

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